Using the fmt command (with examples)

The fmt command is a useful tool for reformatting text files, allowing you to adjust the line width and join paragraphs together. It is particularly helpful when you need to format text to fit within a specific width, such as when preparing documents for printing or displaying on a limited space.

Reformatting a file

The simplest use case of the fmt command is to reformat a file by joining its paragraphs and limiting the line width. Here is an example command:

fmt path/to/file

Motivation: The motivation for using this example is to demonstrate the basic usage of the fmt command. It is useful when you want to reformat a file and make it easier to read by removing extra line breaks and adjusting the line width.

Explanation: The path/to/file argument specifies the path to the file that you want to reformat. The fmt command will then process the file and output the reformatted text.

Example output:

This is a sample text file.
It contains multiple paragraphs and line breaks.

Reformatting this file using the `fmt` command
will eliminate unnecessary line breaks and limit the line width to a specified number of characters.

This reformatted text file will be easier to read and maintain.

Limiting output line width

In some cases, you may want to control the maximum width of the output lines. The -w option allows you to specify the desired width. Here is an example command:

fmt -w n path/to/file

Motivation: The motivation for using this example is to show how you can limit the output line width to a specific number of characters. This can be useful when you need to fit the formatted text within a particular width constraint, such as when preparing text for publication or display purposes.

Explanation: The -w option followed by the number n specifies the maximum width of the output lines. The path/to/file argument specifies the file to be reformatted. The reformatted text will have lines that are at most n characters wide.

Example output:

This is a sample text file. It contains multiple paragraphs
and line breaks.

Reformatting this file using the `fmt` command will
eliminate unnecessary line breaks and limit the line
width to a specified number of characters.

This reformatted text file will be easier to read and
maintain.

Retaining line breaks within paragraphs

By default, the fmt command joins lines shorter than the specified width together. However, in some cases, you may want to retain the line breaks within a paragraph but still reformat the text. The -s option allows you to achieve this. Here is an example command:

fmt -s path/to/file

Motivation: The motivation for using this example is to demonstrate how to retain line breaks within paragraphs while still reformatting the text. This can be useful when you want to adjust the line width but maintain the original formatting within each paragraph.

Explanation: The -s option instructs the fmt command to retain line breaks within paragraphs. The path/to/file argument specifies the file to be reformatted. The reformatted text will have adjusted line widths but will preserve the original line breaks within each paragraph.

Example output:

This is a sample text file.
It contains multiple paragraphs
and line breaks.

Reformatting this file using the `fmt` command will eliminate unnecessary line breaks and limit the line width to a specified number of characters.

This reformatted text file will be easier to read and maintain.

Uniform spacing between words and paragraphs

The fmt command also allows you to specify uniform spacing between words and paragraphs. This can be helpful when you want to format the text with consistent spacing for aesthetic or readability reasons. The -u option enables this functionality. Here is an example command:

fmt -u path/to/file

Motivation: The motivation for using this example is to illustrate how you can achieve uniform spacing between words and paragraphs. This can be useful when you want to create a visually appealing and readable text format.

Explanation: The -u option instructs the fmt command to apply uniform spacing. The path/to/file argument specifies the file to be reformatted. The reformatted text will have one space between words and two spaces between paragraphs.

Example output:

This is a sample text file. It contains multiple paragraphs and line breaks.

Reformatting this file using the `fmt` command will eliminate unnecessary line breaks and limit the line width to a specified number of characters.

This reformatted text file will be easier to read and maintain.

Conclusion

The fmt command provides a versatile set of options for reformatting text files, giving you control over the line width and paragraph structure. Whether you need to adjust the formatting for printing or enhance the readability of a text file, the fmt command can be a handy tool in your arsenal.